Folia Conchyliologica 60 Altab
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An enigmatic rock-dwelling land snail from southernmost Iberia (Mollusca, Gastropoda, Helicidae) Cristian Altaba, Félix Jiménez To cite this version: Cristian Altaba, Félix Jiménez. An enigmatic rock-dwelling land snail from southernmost Iberia (Mollusca, Gastropoda, Helicidae). Folia Conchyliologica, Cédric Audibert, 2021, pp.35-44. hal- 03144942 HAL Id: hal-03144942 https://hal.archives-ouvertes.fr/hal-03144942 Submitted on 24 Feb 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Folia Conchyliologica, 60 Février 2021 An enigmatic ro ck - dwelling land snail from southernmost Iberia (Mollusca, Gastropoda, Helicidae) 1,2 3 Cristian R. ALTABA & Félix RÍOS JIMÉNEZ 1 Llevant Natural Park, Department of the Environm ent, Government of the Balearic Islands, Ap. 76, 07570 Artà, Balearic Island s, Spain. 2 Research Group on Human Evolution and Cogniton (EVOCOG), University of the Balearic Islands, 07072 Palma, Balearic Islands, Spain; [email protected] (correspondi ng author). 3 Sociedad Gaditana de Historia Natural, c/Madreselva s/n, 11408 Jerez, Cádiz, Spain. http://zoobank.org/References/7dab39f0 - 43d3 - 4804 - 976c - 71a1de49f801 Abstract - A new species and genus of helicid land snail, Tartessiberus cilbanus , is herein described from the extreme south of continental Spain. In spite of being fairly large and conspicuous, it has hitherto remained unknown due to its highly restricted ecologi cal and geographic range – it is apparently restricted to the core of Serra nı́a de Grazalema, an elevated karstic area receiving the highest rai n fall in all of Iberia because of its location in proximity to the Strait of Gibraltar. The genital anatomy of the new species indicates it belongs within the tribe Allognathini, but it re mains unclear whether it is closer to the southeastern Iberian endemic Iberus , or to Allognathus from the Balearic Islands. Its radula and shell are reminiscent of the latter, but th is might be a case of convergence on crevice dwelling and feeding on bare rock surfaces. This rare, restricted - range endemic deserves conservation attention. Keywords - Endemism, karst, Grazalema, Andalusia, Allognathini, genitalia, rock - scrapping radula. Resumen - Se describe una nuevo género y especie de caracol terrestre he lı́cido, Tartessiberus cilbanus , del extremo meridional de España continental. A pesar de ser bastante grande y llamativo, ha permanecido desconocido hasta ahora debido a su limitada distribucion ecológica y geográfica; parece restringido al núcleo de la Se rranı́a de Grazalema, un macizo cárstico que recibe la mayor pluviosidad de toda Iberia como consecuencia de su proximidad al Estrecho de Gibraltar. La anatomı́a genital de la nueva es pecie indica que pertenece a la tribu Allognathini, pero no está claro si es más próxima a Iberus , endémico del sureste de la Penı́nsula Ibérica, o bien a Allognathus , de las Islas Baleares. Su rádula y concha recuerdan las de este último, pero esto podrı́a ser un caso de convergencia a habitar grietas y alimentarse en superficies rocosas desnudas. La conservación de este endemismo raro y circunscrito merece atención. Palabras clave – Endemismo, carst, Grazalema, Andalucı́a, Allognathini, genitalia, rádula litoerosiva. Introduction During the last six years we have aimed at colle cting and studying a puzzling land snail from southernmost Spain. It is herein described as a new species and genus. In spite of being fairly large and conspicuous, it has hitherto remained unknown due to its highly restricted ecological and geographic ran ge. Serranı́a de Grazalema is an elevated (1654 m) set of abrupt ranges at the limit between Cádiz and Má laga provinces, representing the wersternmost edge of the Subbetic Ranges. It receives the highest rainfall in all of Iberia, surpassing 2,400 mm annua l mean in core areas, with years reaching over 3,200 mm. This is the combined effect of being located in proximity to the Strait of Gibraltar and standing as a major channel for humid winds ( N ARANJO - B AREA & al ., 2017). The local climate is typically Medite rranean, with a long, dry summer with temperatures above 20 ºC, and a cool (below 10 ºC) rainy winter. Su ch extreme climate has produced an impressive karst geomorphology, mostly on Jurassic limestones, exarcerbated by glacial processes and more recently d eforestation ( D ELANNOY , 1998). This unique setting harbors a highly endemic biota ( B EL O RTEGA & A PARICIO G ARCIA , 1989). It is a unique biogeographic enclave, encompassing less than 1% of Andalusia ( D OMINGUEZ V ILCHES , 1988). It belongs into the Rondense di strict, which constitutes the westernmost edge of the mountains included in the Mediterranean - Ibero - Atlan tic region ( R IVAS - M ARTINEZ & al ., 1997; Mota & al., 2002). The Iberian endemic genus Iberus Montfort, 1810 includes an uncertain number of species, ye t it is clearly - 35 - Folia Conchyliologica, 60 Février 2021 diversified in the Betic area of southeastern Iberia ( R OSSMASSLER , 1854 - 1859; S CHMIDT , 18 55; G ARCIA S AN N ICOLAS , 1957; C OBOS , 1980; E LEJALDE & al ., 2008a,b; S CHILEYKO , 2006; W ELTER - S CHULTES , 2012). It belongs within the Allognathini, a smal l tribe of helicines ( K NEUBUHLER & al . 2019; H OLYOAK & al ., 2020) including the well - known Cepaea Held, 1 838 and Caucasotachea Boettger 1909, the Western Mediterranean Pseudotachea Boettger, 1909 , and also two genera endemic to the Balearic Islands, Allogn athus Pilsbry, 1888 and Iberellus Hesse, 1908. The latter two genera have been considered synonymous, but we refuse such proposal on the basis of the striking anatomical and ecological differences separating them ( A LTABA , 1991 ; W ELTER - S CHULTES , 2012). Th e Western Mediterranean region is a dynamic biogeographic setting; in spite of common misinterpretations, both vicariance and dispersal have played important roles in shaping the distributions of endemic taxa ( A LTABA , 1998, 2014, 2021). Our finding of a hi therto unknown species of allognathine in Serranı́a de Grazalema, obviously well adapte d to local rocky habitats, poses a number of phylogenetic and biogeographical questions, as it shares traits and ecology with both the continental Iberus and the insular Allognathus . Material and methods Collecting in Serranı́a de Grazalema was performed by FRJ repeatedly, with special emphasis on karstic formations. Live specimens were found aestivating in crevices, or active after heavy rains. They were observed and pho tographed, and then drowned and preserved in 80% ethanol. Dissections were performed by CRA under an Olympus SZ - 30 dissecting microscope, with the aid of fine, sharpened twizzers, iridectomy scissors and entomological pins. The radula, jaw and dart were e xtracted, prepared and mounted, and observed under a Leica DME compound micr oscope. Drawings were prepared on the basis of various photographs and direct observation. The following measures were taken on shells (as defined by B REURE & V EGA - L UZ , 2020): hei ght (H), width (W), aperture height (AH), aperture width (AW), last whorl he ight (LW), number of whorls (NW). Anatomical terminology follows G IUSTI & al . (1995). Abbreviations used in figures are as follows: AG: albumen gland FO: free oviduct AP: annular pad G: glans of penial papilla BC: bursa co pulatrix GA: genital atrium BCD: diverticulum of bursa copulatrix PDP: proximal cavity of distal penis BW: body wall PE: proximal epiphallus CD: copulatory duct PPDP: papilla in the proximal cavity of the distal CLS: crest - like structure penis DBC: duct of bursa copulatrix PI: pilas ter DDP: distal cavity of distal penis POS: prostatic ovispermiduct DE: distal epiphallus PP: proximal penis DG: digitiform glands PR: penial retract or muscle DP: distal penis PS: penial sheath DS: dart sac PV: proximal vagina DV: distal vagina PW: penial wall E: epiphallus T: talon F: flagellum UOS: uterine ovispermiduct FHD: first hermaphrodite duct VD: vas deferens The material on which this study is based has been deposited in th e following collections: Museographic Collection of the first author (CRA), Sociedad Gaditana de Historia Natural (SGHN), Museu Balear de Ciències naturals (MBCN), Muséum d'Histoire Naturelle de Genève (MHNG). Systematics Family Helicidae Rafinesque, 18 15 - 36 - Folia Conchyliologica, 60 Février 2021 Subfamily Helicinae Rafinesque, 1815 Tribe Allognathini W esterlund, 1903 Tartessiberus gen. nov. http://zoobank.org/NomenclaturalActs/625e223a - 28bf - 4ae2 - 90c0 - 7b 4d3b179f3e Diagnosis. - Mid - sized helicines with thin semiglobose shell, rock - scrapping radula, stout ridged mandible, exceedingly long flagellum and diverticulum of bursa copulatrix, proximal cavity of distal penis limited by two medial papillae and havi ng a small papilla on the inner wall, crest - like structure at distal end of penis, and four - edged spear - shaped dart with blades slightly enlarged near edge in the distal part. Type species. - Ta rtessiberus cilbanus Altaba & Rı́os, spec. nov. Species includ ed. - Monotypic. Etymology. - A combination of